Split piston for internal-combustion engines and analogous uses



July 17, 1923. 1,462,089

G. T. LEWIS SPLIT PISTON FOR INTERNAL COMBUSTION ENGINES AND ANALOGOUS USES Filed Sept. 19. 1922 FIG. 2. F153.

iii!

ATT ORNVE? Fatented daily i7, @230 PISTON FOR INTERNAL-COMBUSTION ENGINES AND ANALOGOUS USES.

Application filed September 19, 1922. Serial No. 589,096.

To all whom it may concern:

Be it known that I, Gnoncn T. LEWIS, of Middleville, in the county of Herkimer, in the State of New York, have invented new and useful Improvements in Split Pistons for Internal-Combustion Engines and Analogous Uses, of which the following, taken in connection with the accompanying drawings, is a full, clear, and exact descri tion. s This invention relates to sectional pistons for internal combustion engines and anal- 0 one uses where it is desired to maintain c ose fitting joints between the piston and bore of the cylinder for maximum compression and suction, according to the use to which the piston is put.

The main object is to provide a two:p1ec e piston of this character divided longitudinally in such manner that the opposed sections ma slide telescopically one upon the other un er the action of expanding springs.

to automatically compensate for wear and thereby to effects close running joint between the piston and bore of the cylinder Anoer object is to bring the telescoping parts of the sections close to the head of the pn so that the overlapping portions may strenen the head and impart the desired axial rigidity thereto for resisting the strains incidental to compression and expansion of the explosive mixture and at the same time holding the sections in fixed axial relation while permitting their lateral expansion under the tension of the springs.

Other objects and uses relating to specific parts of the piston will be brought out in the following description.

In the drawings:

Figures 1, 2 and 3 are respectively a top plan, an inverted plan and a side elevation of a piston embodying the various features of my invention.

Figure 4 is alon 'tudinal sectional view taken on line 4-4, igure 1.

Figure 5 is a transverse sectional taken on line 5-5, Figure 2.

Figures 6 and 7 are rspective views of op ite halves of the piston.

' illustrated, this piston is made in two parts, or substantially semi-cylindrical half sections 1 and -1'-, in so far that the view ntajogfortion of the length of the piston is dlvid diametrically at -2-=' from its inner and to within a relatly ly Short distance from the outer end or hcadwhere the division line is ofi'set at opposite sides of the plane of diametrical division. That is, the head end of one section, as 1-, is provided with a flange or tongue 3- extendin to one side of the division line 2, an is also provided with a recess or groove -4-- extending to the opposite side of the diamet rical division line, while the head end of the other section, as .1'-, is provided with a recess or groove 5, extending to the 05 cess 5 will be coincident with the bot- 76 tom wall of the recess -4. y In like manner the flanges or ton es s 3- and 6- extend in opposite directlons from the diametrical division -2-- at,

right angles thereto, so that the inner face 00 of the flange 6 will be substantiall co incident with the outer face of the an -3-. The thickness of the flange 3 1s substantially equal to the axial depth of the groove or recess '5', while the thickness of the flange -6 is substantially equal to the axial epth of the recess 4-, which brings the outer end faces of both piston 7 sections in substantially the same plane at right angles to the axis of the piston, while .the transverse width of theflange 6- will be substantially twice the width of that of the flangev3-, and in like manner the transverse width of the groove 5 will be approximately half the width of the groove 5 4 a The outer edges of the flanges 3 and 6- and corresponding bases of the grooves 4- and --5- are substantially strai ht and parallel, and by reason of the fact t at v they extend in opposite directions be ond the; axis of the piston and also beyon the diametrical division -2,-it is evident that the lengths of the outer edges of said flanges are less than the diameter of the piston in that they terminate in the periphery thereof.

By diduing the piston longitudinally in the manner just described, the flange 3 of the section -,--1-- will overlap a' ortion of the section 1-- at one side oft c axis 1 ofthe piston, while the flange -'-6- of the section -'1 will overlap upon the section -1 at the opposite side of said axis, thereby establishing what may be termed an interlocking tongue and groove connection between the head ends of both sections and permitting those parts to slide transversely one upon the other.

The intermediate portions of the sections --1 and -1'-- are provided with diametrically extending openings 7-. at right angles to the plane of division -2- and parallel with the flanges -3 and --6-, some distance inwardly beyond said flanges for receiving the opposite ends of a coupling pin -8, which in turn is adapted to receive the adjacent end of a suitable connecting rod or pitman by which the piston is connected to the crank shaft of the engine in the usual manner not necessary to herein illustrate or describe.

One end of the coupling pin 8- may be secured against axial movement to the adjacent piston section, as 1', by means of a set screw 9, while the opposite end extends loosely into its bearing 7- in the corresponding piston section to permit the piston sections to slide or expand laterally.

relatively to each other.

Suitable means is provided for yieldingly urging the piston sections against the slde wa s of the bore of the cylinder, and for this purpose a pair of light coil sprin s -10-- are arranged in transversely exten ing sockets --11-- in one-of the piston sections, as 1--, preferably in the fla -3-, so as to bear against the base of t e groove 5 of the opposed section --1.

It is evident, however, that suitable springs may be placed in other relations between the piston sections for expanding said sections a ainst the walls of the cylinder and there ore I do not wish to limit myself to the precise location and construction of the s rings.

The periphery of the piston may be provided with one or more annular grooves, as 12- and 12--, located preferably above and beneath the coupling pin 8- for re ceiving any suitable form of piston rings not shown and not necessary to herein illustrate and describe, since the use of piston rings is well known. It is desirable, however, to make the u per groove 12-- of suflicient length axi 1y to receive a pair of piston rings arranged edge to edge for reducing the liability of leakage of gas or oil from or to the combustion chamber.

meaosa As previously stated, the edges of the flanges 3 and -6- are straight and parallel with the diametrical division -2, and by constructing said flanges so that the flange of each section will overlap upon portions of the other section, adds strength to the head of the piston to resist the strains incidental to compression and expansion of the exploded gases and also reduces the liability of leakage at the joints, and the flange of each section forms a guide for holding the sections against relative axial movement while permitting their relative transverse movement.

What I claim is:

l. A piston composed of opposite sections, a coupling pin extendin diametrically through both sections at su stantially right angles to the plane of their meeting edges, the meeting sides of the head end of each section being provided with a laterally pro jecting tongue and a (groove, thetongue of each section being sli able in the groove of the other section.

2. A iston. composed of opposite sections, a con ing pin extendin diametrically throug both sections at su stantially right angles to the plane of their meeting edges, the meeting sides of the head end of each section being provided with a laterally pro jecting tongue and a groove, the tongue of each section being slidable in the groove of the other section, and means for exerting radial pressure upon both sections in the direction of the axis of the coupling pin.

3. A piston comprising opposed sections having alignedradial openings between their ends, a couplin pin inserted in said openings and extendlng diametrically of the piston at right angles to the meeting faces of the sections, each section having a tongue and a groove extending radially from said meeting faces in the direction of the axis of the coupling pin, the tongue of each section being slidably engaged in the groove of the other section, the edges of the tongue and bases of the grooves being substantially straight and disposed at right angles to the axis of the coupling pin.

In witness whereof I have hereunto set my hand this 9th day of September, 1922.

GEORGE THOMAS LEWIS. Witnesses:

HERBERT C. Mommcux, CARRIE TAFI. 

